TITLE:   GCN CIRCULAR
NUMBER:  24955
SUBJECT: GRB 190701A: Swift/UVOT Upper Limits
DATE:    19/07/01 22:18:53 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>

M. H. Siegel (PSU) and T. N. Ukwatta (LANL)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190701A
145 s after the BAT trigger (Ukwatta et al., GCN Circ. 24934).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al. GCN Circ. 24940)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           145          295          147         >20.3
u_FC               303          553          246         >19.8
white              145         6776          727         >21.2
v                  629        11104          409         >19.3
b                  559         6570          432         >20.6
u                  303         6365          659         >20.6
w1                 677         6160          432         >19.9
m2                 652         5955          432         >19.3
w2                 610        10926         1158         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.59 in the direction of the burst
(Schlegel et al. 1998).